These are the two most famous submachine guns of World War II: the German MP-40 and the Soviet PPSh.
The first was developed by the German gunsmith Heinrich Olmer in 1938 year. Those who call this submachine gun "Schmeisser" - wrong. Hugo Schmeisser had nothing to do with him. The only thing he had was a patent for a store and a mechanism for latching a store.
The PPSh submachine gun was developed by the Soviet designer Georgy Shpagin and put into service at the very end of 1940 of the year. From the very beginning, PPSh was designed so that it was extremely easy to produce, even in enterprises that did not have complicated tooling and serious machines. Many other countries were forced to develop such weapon already in the process of war. In the USSR, the most simple in production and technological PP appeared before the war.
To find out which of the pistols and machine guns is better, the experts of the Kalashnikov concern carried out several tests.